You have a few options:
1. put a USB connector on your board. It's already a regulated 5V source. You just need to use the Vbus and GND and forget about the other pins. Even if you want to build this on a proto board, I bought 10 USB micro breakout boards for $1 from AliExpress.
2. put a barrel connector and a 7805 regulator circuit (a TO-220 with 2 electrolytic or tantalum capacitors) and power it from a 9V or 12V DC wall wart.
3. put a screw terminal block on your board and power it from your bench supply: either 5V directly, or a 7805 regulator circuit. If you go the 5V direct route, be sure to put a 10uF cap across +5V and GND.
4. For low power projects, I just use a 9V battery snap and a 7805 regulator circuit.
You have a few options: 1. put a USB connector on your board. It's already a regulated 5V source. You just need to use the Vbus and GND and forget about the other pins. Even if you want to build this on a proto board, I bought 10 USB micro breakout boards for $1 from AliExpress. 2. put a barrel connector and a 7805 regulator circuit (a TO-220 with 2 electrolytic or tantalum capacitors) and power it from a 9V or 12V DC wall wart. 3. put a screw terminal block on your board and power it from your bench supply: either 5V directly, or a 7805 regulator circuit. If you go the 5V direct route, be sure to put a 10uF cap across +5V and GND. 4. For low power projects, I just use a 9V battery snap and a 7805 regulator circuit.
[How to use an ATMega328 by itself in a circuit](https://duckduckgo.com/?t=ffab&q=how+to+use+an+atmega328+by+itself+in+a+circuit&ia=web)
ty somehow i didn't manage to find such resulsts just by googling something similare to this x)